1. Field of the Invention
This invention relates to a picture information processing method and apparatus and an entertainment apparatus. More particularly, it relates to such a picture information processing method and apparatus and an entertainment apparatus in which a picture is generated by iterated transformation decoding processing.
2. Description of the Related Art
As a conventional typical picture compression system, there is known a so-called JPEG (Joint Photographic Coding Experts Group) standardized by ISO. This JPEG system uses the DCT (discrete cosine transform) and is known to achieve optimum encoded or decoded pictures subject to assignment of a larger volume of bits. However, if the number of encoding bits is decreased, block distortion proper to DCT becomes outstanding to render subjective deterioration more apparent.
On the other hand, a picture compression system utilizing the IFS (iterated function systems) is recently stirring up notice. This system exploits the self-similarity of a picture on the premises that, if a portion of the picture is taken out, there exists in the picture another picture portion strongly resembling the taken-out picture portion. This IFS system has a merit that decoding is not dependent at the time of decoding on resolution because the block distortion is not apparent as in JPEG and self-similarity between blocks of different sizes in the picture is exploited. This IFS system, also termed fractal encoding, is retained to be promising in a variety of the fields of application.
The technique described in Japanese Laying-Open Patent 5-57062 exploits the function proper to the fractal encoding, that is the function of restoring the picture with a smaller information volume, in a game machine. Referring to FIG. 1, showing a block diagram for this technique, there are connected, to a system bus 62 to which is connected a CPU 50, a work VRAM 51, a ROM 52, an external interface (I/F) 53, a fractal drawing unit 55, a GDC (graphics display controller) 57 and a keyboard (KB) I/F 60. To the external I/F 53 is loaded a game ROM 54. A VRAM (video RAM) 56 is connected to the fractal drawing unit 55 and to the GDC 57, while a CRT (cathode ray tube) 59 is connected via a graphic I/y 58 to the GDC 57 and a keyboard 61 is connected to the KBI/Fxy 60.
The operation of the above-described configuration is as follows:
When the game ROM 54 is loaded on the I/F 53, and the power is turned on by actuation of a power source switch, a pre-set amount of the leading end portion of the game software is read from the game ROM 54 for storage in the work VRAM 51. An initial picture contained therein is transferred to the GDC 57, which then expands the transferred initial picture on the VRAM 56 and reads it at a pre-set period in order to transfer the read-out picture to the graphic I/F 58 and output the picture on the CRT 59. On reception of a command entered by a user from the keyboard 61 via KB I/F 60, the CPU 50 reads out corresponding figure data from the work VRAM 51, in accordance with the command, to transfer the read-out data to the GDC 57 or to send a command for movement of the displayed figure to the GDC 57 to update the displayed picture.
In the game software, read out from the game ROM 54 via the external I/F 53 and stored in the work VRAM 51, there are contained, in addition to the conventional control program and figure data, a fractal figure drawing command and a program. The fractal figure drawing command and the program are made up of equations setting out rules for figure formulation (algorithms) and initial values on the starting positions for figure drawing. If data read out from the work VRAM 51 in accordance with the command etc entered from the keyboard 61 is the fractal figure drawing command rather than the figure data, the CPU 50 transfers the command to the fractal drawing unit 55, rather than to the GDC 57. On reception of the command, the fractal drawing unit 55 sequentially generates figure elements, such as line segments, in accordance with the initial values and equations, and expands the generated figure elements on the VRAM 56 to draw natural objects, such as mountains, trees or leaves of the trees, or characters. It is thus possible to draw complex figures of larger data volumes in accordance with the fractal picture drawing commands of a smaller data volume.
In the aforementioned Japanese Laying-Open Patent 5-57062, there is made no specified explanation as to which fractal drawing command should be given to draw which pictures.
In the above-described prior-art example, in which the fractal figure is drawn in accordance with the picture-drawing command, the figures that can be drawn are limited such that there is not provided the function of compressing and restoring the natural pictures or textures at large.
Independently of the above-described technique, there is employed the JPEG system as the compressing encoding technique for a texture (picture) in case of effecting texture mapping to an object shape frequently used in a personal computer or on a game machine. The result is that, since the apparent resolution of the texture is increased on zooming the object shape, the block distortion proper to DCT is enlarged to render the picture deterioration more apparent to give a blurred displayed picture devoid of sharpness.
It is therefore an object of the present invention to provide a picture information processing method and apparatus and an entertainment apparatus whereby a decoded picture less susceptible to deterioration of the picture quality of the texture on zooming the object shape obtained on texture mapping.
A picture information processing apparatus according to the present invention includes main memory means for storage of data containing fractal transformation parameters, picture processing means for effecting iterated transformation decoding using the fractal transformation parameters stored in the main memory means to generate a picture, picture storage means for expanding a picture generated by the iterated transformation decoding, display control means for display-controlling the generated picture, actuation inputting means, and control means for controlling the processing by the picture processing means and the display operation by the display control means responsive to an actuating input from the actuation inputting means.
According to the present invention, an initial picture is restored at the time of effecting iterated transformation decoding using fractal transformation parameters stored in the main memory means and iterated transformation decoding employing the fractal transformation parameters is effected based on the restored initial picture to generate a picture.
By an actuating input, an iteratively transformation decoded picture is generated and decoded. By effecting iterated transformation decoding based on the restored initial picture, the iterative transformation decoded picture can be generated at a high speed with a smaller number of tomes of reiteration.
According to the present invention, a picture is generated by iterated transformation decoding using fractal transformation parameters stored in the main memory means. The picture generated on iterated transformation decoding is expanded on picture storage means. The generated picture is display-controlled and the picture processing and display is controlled responsive to the actuating input from the actuating input means to effect iterated transformation decoding of a picture, such as texture, at an elevated speed responsive to actuation.
Since the initial picture is restored, and a picture is generated by iterated transformation decoding based on the restored initial picture, the iterative transformation decoded picture can be generated at a higher speed than if a picture is generated by iterated transformation decoding from an optional initial picture.
By using a decoded version of a pre-encoded initial picture, the data volume can be reduced for the initial picture.
By providing a geometry calculation unit for effecting high-speed calculation of the geometrical information, such as coordinates of the polygon on which to map the texture, it is possible to obtain a more realistic texture-mapping picture.
By providing a cache memory in the main memory, and by storing and transferring data such as the drawing command or fractal transformation parameters, it is possible to realize an elevated overall processing speed.
By providing a texture cache in the picture processing means, the drawing texture can be accessed and transferred at an elevated speed to elevate the drawing speed.
By directly copying a portion of plural pixels as a transformation unit in a domain block in a range block, at the time of restoring an initial picture and effecting iterated transformation decoding based on the restored initial picture, by way of the contracting picture transformation processing, the volume of calculations can be significantly diminished to enable high-speed processing.
Moreover, by generating an enlarged picture by iterated transformation decoding another enlarged picture generated prior to the first-stated enlarged picture, at the time of effecting zoom display using enlarged pictures of plural stages, the processing volume can be reduced significantly to elevate the processing speed and to realize effective utilization of the work area of the picture memory.